National Repository of Grey Literature 46 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Comparision of leachability of heavy metals from various types of alkali-activated alumino-silicate systems
Smolková, Miroslava ; Kalina, Lukáš (referee) ; Koplík, Jan (advisor)
The work deals with the determination and comparison of leaching of heavy metals from various types of alkali-activated alumino-silicate systems (high-temperature fly ash, blast furnace slag). Such alkali activated materials are capable in their structure effectively encapsulate heavy metals, toxic chemicals or other contaminants, which can be beneficial for the environment. The aim of this work is to obtain a mixture with acceptable mechanical properties that could be useful for the inhibition of these substances. Leachability was tested according to norm ČSN EN - 12457-4, followed by analysis by ICP-OES. The structure of the matrix was investigated using SEM equipped with EDS.
Biocatalysts based on lipases, their immobilization and characterization
Bančáková, Anna ; Voběrková, Stanislava (referee) ; Hermanová, Soňa (advisor)
Bakalárska práca sa zaoberá problematikou imobilizovaných enzýmov. V teoretickej časti sú zhrnuté najnovšie používané metódy imobilizácie, typy heterogénnych nosičov a taktiež praktické využitie imobilizovaných enzýmov v potravinárskom priemysle, medicíne, chemickej analýze, pri produkcii bionafty a bioremediácii. Uvedené sú tiež výhody a nevýhody jednotlivých metód imobilizácie (adsorpcia, zachytenie, kovalentné spojenie a zasieťovanie) plynúce z charakteru spojenia enzýmu a nosiča a výslednej aktivity imobilizovaného enzýmu. Z hľadiska nových typov heterogénnych nosičov práca konkrétne uvádza využitie grafénu, ktorý je pre svoje špecifické fyzikálno-chemické vlastnosti často používaným a skúmaným nosičom v posledných rokoch. V experimentálnej časti bola prevedená imobilizácia komerčného preparátu lipázy (RA), izolovanej z mikroskopickej plesne Rhizopus arrhizus, adsorpciou na polyetyléntereftalát, ktorý bol použitý ako nosič. U voľnej i imobilizovanej formy enzýmu boli stanovené základné parametre ako lipolytická aktivita, teplotné optimum, pH optimum a tepelná stabilita. Aktivita enzýmu bola meraná spektrofotometricky pri vlnovej dĺžke 420 nm. Ako substrát bol použitý roztok p-nitrofenyl-laurátu. U voľného aj imobilizovaného enzýmu bolo stanovené pH optimum 7,2, pokles aktivity bol zaznamenaný pri pH nad 8 a pod 6,5. Väčšia závislosť výslednej aktivity na pH prostredia bola dokázaná u imobilizovanej formy enzýmu. U voľného aj imobilizovaného enzýmu bola pozorovaná najvyššia aktivita pri teplote 30 °C. Pokles aktivity bol pozorovaný po zvýšení teploty nad 50 °C. Po dosiahnutí tejto teploty stabilita rozpustného enzýmu prudko klesala. Avšak tepelná stabilita skúmanej lipázy sa po jej imobilizácii výrazne zlepšila. Imobilizovaná forma enzýmu mala v porovnaní s voľnou formou aktivitu 3,7 %.
Preparation of geopolymeric binders for toxic metals inhibition
Jevická, Lucie ; Kalina, Lukáš (referee) ; Šoukal, František (advisor)
This thesis deals with preparation of geopolymeric binders for inhibition of toxic elements, especially arsenic. It studies influence of content progress of different phases in prepared binders on leachability of As during the setting. The aim of this study is to determine the type of inhibition or the cause of leachability of As in prepared binders respectively. Fly ash from high-temperature coal combustion, slag, cement kiln dust and sodium hydroxide solution were used for experimental works. FT-IR, TG-DTA, XRD analyses after different hydration times were used. The leachates were analyzed by ICP-MS. Calorimetric measurements of tested mixtures fresh pastes were implemented to learn about setting process. Hardened binder specimens were tested for bending and compressive strength.
Nursing process in prevention of immobilization syndrome
Havlasová, Anežka ; Průšová, Kateřina (advisor) ; Hromádková, Jaroslava (referee)
The bachelor's thesis deals with the issue of immobilization syndrome. It aims to point out the risks associated with long-term immobilization, recognize the early symptoms of immobilization syndrome and prevent complications. The theoretical part focuses on the characteristics of the immobilization syndrome in individual organ systems, where related changes and prevention are described in detail. The empirical part consists of a questionnaire survey, which focuses on the knowledge of nurses from the standard and ICU departments. The verified knowledge concerns the prevention and nature of the immobilization syndrome. A total of 99 respondents across the Faculty Hospital in Motola participated in the survey. The obtained data were processed and then the knowledge of nurses was compared based on education, type of workplace and length of practice. Objectives: The aim of the bachelor's thesis was to provide a comprehensive overview of relevant findings on immobilization syndrome. Furthermore, the goal was to find out, through a questionnaire, the nurses' own construction of knowledge about immobilization syndrome. Methods: The investigation was conducted through a quantitative research survey. The self- designed questionnaire was distributed in printed form to practical and general nurses. The...
Imobilizace galaktosidasy a její využití v potravinářské technologii
Dobešová, Natálie
This master‘s thesis deals with the issue of galactosidase immobilization and its use in food technology. β-galactosidase from Kluyveromyces lactis was immo-bilized using two methods, specifically encapsulation and cross-linking. The aim of the encapsulation was to obtain hydrogel capsules formed by a biopolymer matrix based on sodium alginate, crosslinked with calcium chloride for repeated catalytic use. The second chosen method was the enzyme cross-linking on a carrier formed by mag-netic particles modified with chitosan. Enzyme activity was determined spectropho-tometrically using the substrate o-nitrophenyl-β-D-galactopyranoside and p-nitrophenol as a standard. Enzyme activity was evaluated in milk samples and the amount of lactose formed was determined polarimetrically. The experimental results showed that the immobilized enzyme on the chitosan magnetic carrier showed higher activity compared to the sys-tem based on alginate capsules, which was also confirmed during the lactose hydroly-sis process. Lactose hydrolysis was the most efficient using a commercial enzyme and the enzyme immobilized on magnetic chitosan. There was no statically significant difference in the lactose content in milk samples without enzyme and with the use of alginate calcium capsules.
Production of lignin-degrading enzymes by Phanerochaete chrysosporium
Péčiová, Bianka ; Hudečková, Helena (referee) ; Kovalčík, Adriána (advisor)
This diploma thesis deals with the study of the production of ligninolytic enzymes produced by the mold P. chrysosporium and subsequently their immobilization. The theoretical part describes the selected production microorganism, principles of action of ligninolytic enzymes (lignin-peroxidase, manganese-dependent peroxidase and laccase) and methods of their immobilization. In the experimental part, optimal conditions of the production of ligninolytic enzymes by P. chrysosporium were monitored as a composition of culture medium with different glucose content and with using two different inducers: lignin and guaiacol. During the 14-day cultivation cycles, the enzyme activity of lignin-peroxidase, manganese-dependent peroxidase and laccase was monitored on each day of cultivation. Based on the optimized enzyme production procedure, the enzymes were subsequently immobilized by various methods: by method of forming enzyme aggregates (CLEA), adsorption on bacterial cellulose (BC) and a combination of both (CLEA + BC). The CLEA method proved to be the most effective, but there was problem with isolation of enzyme aggregates. Therefore, immobilization on bacterial cellulose associated with the enzymes aggregates was chosen as the most advantageous. With this method, the operational stability of the immobilized enzymes was monitored in 7 consecutive reaction cycles. Subsequently, CLEA and CLEA with BC were used to modify the model phenolic substance, where the alkali lignin was selected. For both sets of immobilizers was confirmed the effect of the enzymes on the lignin structure by measuring the molecular weight (Mw) and polydispersity index (PI).
Chemo-enzymatic synthesis of antiviral prodrugs
Tupec, Michal ; Stiborová, Marie (advisor) ; Indra, Radek (referee)
Lipases have been widely applied in the manufacture of food products and in some areas of the industry, nowadays they are used in synthetic organic chemistry catalyzing the hydrolytic/esterification reactions under very mild conditions in the field of protecting groups or enantiomer resolution. In this study, the commercial lipase from bacterium Pseudomonas fluorescens was immobilized using the sol-gel process into organosilicate materials with propyl, octyl or phenyl substituents. The highest hydrolytic activity was found in the enzyme on the octyl-derived carrier. The immobilized enzymes differ in their hydrolytic activities on 4-nitrophenyl esters of various lengths. Subsequent experiments revealed quite good pH stability of the enzymes in a buffer (incubations in pH 3 through pH 11), as well as good temperature stability in isooctane (incubations at up to 100 řC). The majority of organic solvents seem to have no substantial effect on the lipase activity. The biocatalytic properties were studied on a model compound from the group of the acyclic nucleoside analogues - 9-(2',3'-dihydroxypropyl)adenine (DHPA). It was found for example that the best acyl donors are vinyl esters, that the lipase shows a preference towards longer vinyl esters, that the reaction proceeds faster in non-polar solvents or that it...
Preparation of pharmaceutical formulations based on polymeric and lipid carriers
Kubačková, Jana ; Zbytovská, Jarmila (advisor) ; Panáček, Aleš (referee) ; Štěpánek, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Jana Kubačková Supervisor Assoc. Prof. Jarmila Zbytovská, Mgr., Dr. rer. nat. Co-supervisor PharmDr. Ondřej Holas, PhD. Title of Doctoral Thesis Preparation of pharmaceutical formulations based on polymeric and lipid carriers Nanomedicine allows application of nanoscaled drug delivery carriers to achieve a therapy that can be tailored in terms of e.g. controlled release, site-specific delivery and protection of an active substance. From multiple nanoplatforms available for drug delivery, advantage was taken of biocompatible and biodegradable polymers and lipids to enable targeted intracellular delivery, delivery of a poorly water-soluble drug and delivery of a sensitive macromolecule. In the study with biodegradable polymeric nanomaterial we worked with experimental poly(lactic-co-glycolic acid) (PLGA) polymers. The formulations were optimised for targeting to phagocytic macrophages - of size up to 300 nm and negative surface charge. For this purpose, two linear and one branched PLGA were screened in combination with one of four surfactants in low concentrations (0.1-1%). These PLGA polymers were formulated into nanoparticles and loaded with a hydrophilic fluorescent dye Rhodamine B...
Preparation of pharmaceutical formulations based on polymeric and lipid carriers
Kubačková, Jana ; Zbytovská, Jarmila (advisor) ; Panáček, Aleš (referee) ; Štěpánek, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Jana Kubačková Supervisor Assoc. Prof. Jarmila Zbytovská, Mgr., Dr. rer. nat. Co-supervisor PharmDr. Ondřej Holas, PhD. Title of Doctoral Thesis Preparation of pharmaceutical formulations based on polymeric and lipid carriers Nanomedicine allows application of nanoscaled drug delivery carriers to achieve a therapy that can be tailored in terms of e.g. controlled release, site-specific delivery and protection of an active substance. From multiple nanoplatforms available for drug delivery, advantage was taken of biocompatible and biodegradable polymers and lipids to enable targeted intracellular delivery, delivery of a poorly water-soluble drug and delivery of a sensitive macromolecule. In the study with biodegradable polymeric nanomaterial we worked with experimental poly(lactic-co-glycolic acid) (PLGA) polymers. The formulations were optimised for targeting to phagocytic macrophages - of size up to 300 nm and negative surface charge. For this purpose, two linear and one branched PLGA were screened in combination with one of four surfactants in low concentrations (0.1-1%). These PLGA polymers were formulated into nanoparticles and loaded with a hydrophilic fluorescent dye Rhodamine B...
Tandemová hmotnostní spektrometrie sfingolipidů s aplikací pro metabolické studie a diagnostiku sfingolipidos
Kuchař, Ladislav
In recent years, mass spectrometry (MS) become the dominant technology in lipidomic analysis and widely influenced research and diagnosis of diseases of lipid metabolism, e.g. lysosomal storage disorders (LSD) characterized by impairment of the lysosomal functions. Defects in lysosomal processing of sphingolipids SFL belong to the category of sphingolipidoses. This condition has severe and even fatal clinical outcome. The primary aim of this work was to establish quantitative and qualitative methods of SFL analysis useful for research and diagnosis of LSD. At first, semisynthesis of mass labeled lipid standards utilizing immobilized sphingolipid ceramide N-deacylase was performed. Established methods of quantitative analysis were then used to prove the increased excretion of urinary SFL in LSD with characteristic storage in the kidney. Determination of excreted urinary SFL was found useful for differential diagnosis of prosaposin and saposin B deficiences for which routine enzymology is failing. MS also enabled monitoring of individual molecular species (isoforms) of SFL, which led to the finding that their urinary pattern is changing in some LSD. This resulted in the development of new screening method in dry urinary samples based on isoform profile evaluation. Another MS application referred to...

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